The present invention describes a compound having biological activity which has been isolated from the Aloe barbadensis plant. This heretofore-unreported compound, systematically named 8-C-.beta.-D-[2'-.omicron.-(E)-cinnamoyl]glycopyranosyl-2-[(S)-2-hydroxy]p ropyl-7-methoxy-5-methylchromone; has a molecular weight of 541 Da, and the following chemical structure: ##STR1## This compound exhibits potent anti-inflammatory activity as measured in vivo assays. The compound has also been shown to inhibit EGF-induced DNA synthesis in in vitro testing in epithelial cell lines.
Exudates from aloe plants have been employed for centuries as folk remedies for the treatment of burns, sores and other wounds. In recent years, a great deal of research has been concentrated on identifying aloe components which have clinical activity. Two factors which prompt this interest are aloe's propensity to lose at lease some of its therapeutic properties shortly after harvesting, and the desire to eliminate components which may be harmful--e.g., certain anthraquinones. See, e.g., McAnalley, U.S. Pat. No. 4,966,892. The results of these research efforts suggest that the aloe plant contains several components which have wound-healing properties.
The literature contains a report of a 5-methylchromone C-glucoside which has been identified in Cape Aloe, viz., 2-acetonyl-7-.omicron.-.beta.-D-glucopyranosyl-8-C-.beta.-D-[2'-.omicron.- (E)-p-coumaroyl]glucopyranosyl-5-methyl-chrome. Giovanna Speranza, P. Gramatica, G. Dada, P. Manitto, "Aloeresin C, A Bitter C,.omicron.-Diglucoside from Cape Aloe", Phytochemistry, 1985, 24(7):1571-1573. This prior art compound has a molecular weight of 556.5 Da, the glucosylation group is coumaric acid, not cinnamic acid, and no biological activity is ascribed to the compound.
Other reports of chromones in aloe are found in the literature. "Aloe Revisited--The Structure of Aloeresin A", P. Gramatica, D. Monti, G. Speranza, P. Manitto, Tetrahedron Letters, 1982, 23(23):2423-2424; "Chromones in Aloe Species Part 1. Aloesin--a C-glucosyl-7-hydroxy-chromone", D. K. Holdsworth, PM, 19(4):322-325; "Structure Determination of Polysaccharides in Aloe arborescens var. natalensis", Akira Yagi, H. Nishimura, T. Shida, I. Nishioka, Planta Medica, 1986, 213-218; "Chromones in Aloe Species Part II--Aloesone", D. K. Holdsworth, PM, 22(1):54-58; and "A C-Glucosylated 5-Methylchromone from Kenya Aloe", Giovanna Speranza, G. Dada, L. Lunazzi, P. Gramatica, P. Manitto, Phytochemistry, 1986, 25(9):2219-2222.